Bayesian analysis of mixture modelling using the multivariate t distribution

A finite mixture model using the multivariate t distribution has been shown as a robust extension of normal mixtures. In this paper, we present a Bayesian approach for inference about parameters of t-mixture models. The specifications of prior distributions are weakly informative to avoid causing nonintegrable posterior distributions. We present two efficient EM-type algorithms for computing the joint posterior mode with the observed data and an incomplete future vector as the sample. Markov chain Monte Carlo sampling schemes are also developed to obtain the target posterior distribution of parameters. The advantages of Bayesian approach over the maximum likelihood method are demonstrated via a set of real data.     

Olive Oil Consumption in Greece: A Microeconometric Analysis

In this paper, the factors affecting at-home demand for three types of oils and fats in Greece, with emphasis on olive oil, are investigated using the linear approximation of the Almost Ideal Demand System and family budget survey data. To overcome the econometric problem created with the existence of zero expenditure, a generalization of the two-stage Heckman procedure is employed. In order to investigate the role of self-consumption, two different samples were used. The first includes all households; the second excludes those that acquire olive oil only from own production. According to the results, there are important differences in the first stage of the decision process between the two samples. Unlike the first stage, the second stage of the decision process found no important differences between the results for the two samples.     

群体决策支持系统的模型库研究

通过对传统模型及模型库的分析,指出其在网络环境下具有难以实现共享的不足.从模型在网络上共享及其软件实现的角度,在分布式网络数据库环境下,利用分布式网络数据库技术,设计了模型库的结构和机理;提出了模型库的构造方法;对模型库的内部控制方式进行了设计;提出了模型库对群体决策的支持方式;客户端的决策成员对模型库的共享与访问方法.     

GMM tests for the Katz family of distributions

Generalized method of moments (GMM) is used to develop tests for discriminating discrete distributions among the two-parameter family of Katz distributions. Relationships involving moments are exploited to obtain identifying and over-identifying restrictions. The asymptotic relative efficiencies of tests based on GMM are analyzed using the local power approach and the approximate Bahadur efficiency. The paper also gives results of Monte Carlo experiments designed to check the validity of the theoretical findings and to shed light on the small sample properties of the proposed tests. Extensions of the results to compound Poisson alternative hypotheses are discussed.     

论完善我国的破产和解制度

破产和解制度对于维护债务人的合法权益、实现债权利益的最大化和维护社会的稳定发挥着重要的作用。但随着社会经济的发展,该制度日益暴露出一些弊端。建议制定统一的破产法法典时,主要从减少行政干预、实行彻底的和解分离主义、放宽和解的原因和健全监督机制等几个方面对现行破产和解制度进行完善。     

我国深化素质教育改革的主要对策

目前我国素质教育改革的重点应是尽快启动素质教育评价体系建设国家研究项目,积极推进高校招生制度改革,促进学生身心协调健康成长,加快推进中小学实施小班化教学和加强农村师资建设。力争在较短的时间内实现高等教育质量的根本性恢复,稳步推进教育管理体制改革为素质教育改革目标的实现提供制度环境支持。     

A Bayesian Adjustment for Covariate Misclassification with Correlated Binary Outcome Data

Estimated associations between an outcome variable and misclassified covariates tend to be biased when the methods of estimation that ignore the classification error are applied. Available methods to account for misclassification often require the use of a validation sample (i.e. a gold standard). In practice, however, such a gold standard may be unavailable or impractical. We propose a Bayesian approach to adjust for misclassification in a binary covariate in the random effect logistic model when a gold standard is not available. This Markov Chain Monte Carlo (MCMC) approach uses two imperfect measures of a dichotomous exposure under the assumptions of conditional independence and non-differential misclassification. A simulated numerical example and a real clinical example are given to illustrate the proposed approach. Our results suggest that the estimated log odds of inpatient care and the corresponding standard deviation are much larger in our proposed method compared with the models ignoring misclassification. Ignoring misclassification produces downwardly biased estimates and underestimate uncertainty.     

中国农村妇女问题研究综述

随着党中央对三农问题的重视,中国农村妇女问题逐渐凸现出来。对近二十年的中国农村妇女研究重新进行阶段划分,并对中国农村妇女研究所涉及的性别与劳动就业分工,农业女性化问题,农村妇女家庭地位及其变化,农村妇女科学文化素质及培训,农村女性劳动力流动及影响因素,农村妇女与贫困,农村妇女与人口再生产,农村妇女与资源、环境和持续发展,农村妇女参政议政等问题,进行多角度的分析说明,从中总结出经验和不足。农村妇女发展要联系农村实际,要针对多方面因素考虑农村妇女发展与农村诸要素之间的关系。农村妇女研究要采取定量与定性相结合的分析方法,从不同地域、不同环境入手分析当地农村妇女的实际情况,以便在今后的研究中得以借鉴。     

构建沈阳自主创新科技投融资体系的途径选择

建立创新型城市离不开多元化、多渠道、多层次的科技投融资体系。通过有效的政策安排,不断完善科技投融资体系,对加快沈阳的发展,加速科技创新进程和科技成果转化具有重要意义。本文提出了沈阳自主创新亟待投融资体系的完善,着重分析了沈阳自主创新科技投融资体系的现状和存在的问题,提出了促进沈阳自主创新科技投融资体系完善的途径。     

农村互助合作金融模式绩效分析

互助合作金融是中国农村金融市场的一种创新融资模式，尽管其组织化、制度化经营时间短、经验少，融资能力还很微小，但已经表现出财务上可持续发展的能力，在满足农户小额贷款方面的补充作用十分显著。资金互助合作密切了社会成员的相互关系，改善着农村社会关系，社会整体信用水平、将为之提高。论题分析了《农村资金互助社管理暂行规定》颁布前后农村互助合作金融模式的制度绩效、功能绩效和社会绩效。